Back-pedaling brake



Jan, 6. 1925.

- F. J. OLSEN BACK PEDALING BRAKE Filed Nov. 2. 1923 a MI llatented Jan. 6, 1925;o

BAcKi-:DALING BRAKE.

Application filed November 2, 1923. Serial` No; 672,375.

. Improvements in Back-Pedaling- Brakes;

and do hereby declare the following to be a full, clear, and eXact description of the same. w

This invention rel'ates to back pedalmg brakes of'the kind in which a wedging' member engaging a screw-threaded driving member is accommodated within the gap of a' longitudinally split sliding sleeve mounted inside a hub and adapted tobe expanded into fri'ctional contact with -the' hub by means of the said wedgi'ng member, the latter and the sleeve being so formed as to be moved axially in either di1'ectionby`means of the screw-threaded driving member.

In a previous construction offthis general kind both ends of the splitsleeve were provided with teeth, adapted to engage with teeth formed on a fixed member andon the hub respectively, but the teeth extended only over a comparatively small p'art of each end surface of the sleeve yin order' to allow the same to be expanded and to contract freely Without being cheoked by` the engagem'ent of the teeth with the teeth'of'the said fixed memberA or hub.

ber (su'ch as a cylinder or tubular member) provided with clutch elements at-both 'ends and adapted to be moved axially as a whole togetl'ier with the brake sleeve. The supporting member may be provided with an opening through which the wedging member comes into engagement with the scre-wthreaded driver. By thus mountingV vthe expansible brake sleeve upon such a ,separate supportingrmember whicl'rlatter is not eX- panded ,by the* wedging member it is made possible to provide one end surface or both end surfaces ofV the supporting member with a complete series of clutchteeth-whereby a more reliable engagement is obtained, and if desired the clutch' element at oneeendv off the suppo-rting member may be formed as a conical fri'ction clu'tchelement. As the brake sleeve Vitself is not provided with clutch. elements at its ends 'it is more cheap to' makeV 'than the sleeve` of the vbraking mechanism above referred to and may be renewed at smaller costs. F urthermore it may be made of a material particularly Well suited for braking purposes, such as bronze.

,The opening in the supporting member is preferably provided with edges extending parallel to the aXis of thel hub and serving as al guide vfor the wedging member whereby when the sleeve is expanded thewedging action eXerted bythe wedging member is uni'formly distributed over the whole length of thesleeve. i

An embodiment'of the inventionv is shown in -the drawings in which-'- F igure l is al partial. Vertical section through acoaster hub constructed accordingl to the invention', k'

F igure 2 is a partialhorizontal ,section through the same,

Figur'e 8 is a cross sectio on the line A l3 in 'Figure '1,

Flgure ll is a view of the supporting cylinder adapted to carry the split sleeve and I Figure 5 is a view of the wedgingmember which coa'cts'withthe screw-threaded driving' member and the sleev'e;

a is the fixed shaft, Z) the driving' member with the sprocket 'c' for the spr'oclet Chain, and' d' is the outer' hub.V In the cylindrically bored hub (Z is inserted a 'cylindrica'l-sleeve e which is split andl is of sucha diameter that normally it does not' touch the wall vof the outer hub (Z. The sleeve e is split' longitudinally throughou't' its length and has a part of' the wall thereof remove-d as shown in Figure', and' in the space thus formed a wed'ging me-mber f is inserted.` VThis latter' member has a Curved c'ylindrical' upper face and a'projecti'ng" p'orti'on on' its under surface which is shaped on a heli'calline and ad'apt'ed' to -coact with scre'w threads g formed on, the driving member Z). Both edges of themember f are provided With coarse teeth h with oppositely sloping faces ad'apted' to engage with corresponding face's formed on the edges of the slit inthe sleeve e. The sleeve c is carriedfiupon a holil'ow supporting, cylinder-Z, one end of which is providedV with 'clutch teeth m while the other end is formed as a conical clutch element n adapted to coact lwitha corresponding conicalsurface 0 formedfion the inner' side of the Vhub d. supporting. cylinder at a line near` one edge of` the sleeve, preferably V'by means of two rivets orscrews 71', as shown in Figuros 2 and? m o-n'one end of the cylinder Z as shown.

The nut r is held against rotation by an arm a the end of which is secured to the frame of the vehicle in any well known manner, the arm 'u and the nut fr' acting as a brake anchor. vlnside the outer hub (Z is arranged a flat spring z) of known kind, one end of which slides on the circumference of the cylinder Z, thereby producing a small amount of friction.

r1`he operation of the device is as follows:

rllhe parts being in the position shown in the drawing, the driving member occupies a position so as to allow the outer hub to turn freely so that the vehicle is able to freewheel down hill. On forward pedaling the driving member will displace the wedge f to the right which will cause a displacement of the sleeve c and the cylinder Z so that the conical clutch element n on the right end of the cylinder will engage the conical surface 0. By further forward pedaling the teeth h will more forcibly eng-age with the corresponding teeth of the edges of the sleeve e and expand the same so as to cause it to' bear against the inner surface of the hub d, thereby generating a considerable friction allowing the torque to be transmitted from the driving member to the hub. If now the pedals are kept immobile while the vehicle runs forward, the sleeve e and its supporting cylinder will be displaced to 'the left so that the cone on the right end of the cylinder is disengaged from the conical. surface 0, and the sleeve will be released and contract itself, so that free running can now take place without any hindrance. Owing to the effect of the friction spring 7) the sleeve e is displaced to the left until the teeth on the left end of the cylinder engage the teeth on the nut 1", and on back pedaling the wedge /f will be displaced to the left by the screw threads on the driving member, causing the sleeve e to be expanded and eifecting braking in the well known manner.

Having thus fully described my invention I claim as new and desire to secure by Letters Patent:

1. In a brake mechanism, the combination of an aXle, a hub thereon, a driving member, a brake anchor, a longitudinally movable expansible friction-brake member mounted within the hub, a supporting member carrying said fr1ct1on-brake member, said friction-brake member and supporting member being connected to each other so as to move in unison in the longitudinal and circumferential directions while allowing` expansion and contraction of the friction-brake member, and means actuated by said driving member for connecting said supporting member to said brake anchor by longitudinal movement of the former in the hub and eXpanding said brake member against said hub.

2. In a brake mechanism, the combination of an axle, a hub thereon, having a clutch element, a driving member project-- ing into said hub, a stationary brake support having a clutch element, a longitudinally movable expansibe friction-brake member mounted within the hub, a non-expansible supporting member carrying said friction-brake member and provided with clutch elements at both ends, said friction-brakc member'and supportlng member being connected to each other so as to move 1n umson in the longitudinal and circumferential directions while allowing expansion and contractlon of the frlctlon-brake member, and means actuated by said drivmg member for connecting the clutch element at one end.

of an aXle, a hub thereon, a driving member' projecting into the hub and provided with screw threads, a stationary brake support having a clutch element, a yi'eldingly expansible brake sleeve with-in the hub having one longitudinal slot throughout its length, a wedging member engaging the screw threads of said driving member and adapted to be moved in the slot to thereby expand the brake sleeve against the hub, and a supporting member carrying said brake sleeve and connected thereto so as to move longitudinally and angularly as a'unit therewith and provided with a clutch element, said supporting member being adapted to be moved longitudinally by said wedging member into engagement with the brake support to hold the supporting member and the sleeve stationary, after which the sleeve is' expanded against said hub by further movement of the said wedging member.

4. In a coaster hub, the combination of an outer hub member, an expansible brake sleeve mounted within said hub member and having a longitudinal slot throughout its length, at least one edge of the sleeve adjacent the slot being provided with teeth with oppositely sloping faces, a supporting cylinder surrounded by said sleeve and connected thereto so as to move longitudinally and angularly therewith as a unit and having an opening, a wedging member positione in said slot and having teeth adapted to engage said teeth, and a driving member projecting into said supporting cylinder and provided With screw threads engaged by said Wedging member through the opening in said supporting cylinder.

5. The coaster hub of claim 4, in vvhich one end of the supporting cylinderl is providecl With a circulai' row of clutch teeth and the other end is forined With a conical surface.

6. The coaster hub of claim 4:, in which the brake sleeve is only secured to the supporting cylinder at points in a line near one longitudinal edge of the sleeve.

7. The coaster hub of claim 4, in which the opening of the supporting cylinder falls short of the ends of the same and has straight edges parallel to the axis of the hub, said edges serving as a guide for the Wedging member.

8. In a brake mechanism, the combination of an axle, a hub thereon, a driving member, a brake anchor, a longitudinally movable cylindrical expansible friction brake member having a single slot throughout its length and mounted Witlrn the hub, a supporting member carrying said friction bra-ke member, said friction brake member and supporting member being connected to each other so as to movein unison in the longitudinal and circumferential directons while allowing expansion and contracton of the friction brake member, and means actuated by said driving member for connecting said Supporting member to said brake anchor by longitudinal movement of the former in the hub and expanding said brake member against said hub.

9. In a brake mechanism, the combination of an axle, a hub thereon, having a clutch element, a driving member projecting into said hub, a stationary brake support having a clutch element, a longitudina-lly movable expansible friction brake member mounted Within the hub, a non-eXpa-nsible supporting member carrying said friction brake member and provided With clutch elements at both ends, said friction brake member and supporting member being connected to each other so as to move in unison in the longitudinal and circumferential directions While allowing expansion and contraction of the a friction brake member, and means actuated by said driving member for connecting the clutch element at one end of said supporting member With the clutch elementlof said stationary brake support by longitudinal movement of the supporting member in one direction in the hub and expanding said brake member against said hub, and for connecting the clutch element at the opposite end of said supporting member With the clutch element of said hub by longitudinal movement of the supporting member in the opposite direction in the hub and expanding said brake member against said hub, Whereby said brake member can be brought into frictional engagement With said hub for braking purposes as Well as for forward driving purposes.

10. The coaster hub of claim 4, in which w one end of the supporting cylinder isprovided With a circular row of clutch teeth and the other end is formed with a conical friction clutch surface.

11. In a coaster hub according to claim 4-, I

Wherein said Wedging member engages the screw threads of said driving member from one side only and is capable of beng released from the driving member by being removed in a direction' perpendicular to the axis of the hub through said opening in the supporting cylinder and said slot in the brake sleeve.

12. In a coaster hub according to claim 4, Wherein the said brake sleeve is of springlike material of a nature such that the sleeve, when brought into frictional engagement With the inner surface of said outer hub member and thereafter released from-the infiuence of said wedging member, is capable of contracting and disengaging itself from the outer hub member Without the aid of any auxiliary spring.

In testimony Whereof I have aflixed my signature in presence of two Witnesses.

FREDERIK J OHANNES OLSEN. VVitnesses: i

GEORGE BLAUR, C. V. HGsTED. 

